Wasatch-Cache National Forest:  In partnership with:  Utah State Parks and Recreation, Friends of the Utah Avalanche Center-Logan, and Utah State University College of Natural Resources.


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Logan area Avalanche Advisory

Friday January 11, 2008

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  It’s Friday January 11th, and it’s about 7:30 in the morning.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Simmons Flexi-ski of Providence.

             Current Conditions:

The mountians around Logan picked up several feet of snow in the last week, and backcountry snow conditions are looking good at all elevations. You’ll find good powder today on most slopes, with some wind carnage in terrain exposed to west winds. The Tony Grove Snotel reports 4/10s of an inch of water or around 6 inches of new snow in the last 24 hrs, and there’s 74 inches of total snow on the ground.  Water-wise the station has climbed to 83 % of average water in the snow for the date.  Even with about 3’ of fresh light powder on the snow surface, trail breaking and powder riding conditions have improved in the last couple days, and I expect that a number of us will make it up into higher terrain this weekend.

            Avalanche Conditions:

Numerous natural new snow avalanches occurred across the region during or right after Wednesday’s storm, and I greatly appreciate the helpful observations you’ve been sending my way.  Of interest, is the number of low elevation avalanches, like wind slab releases near the mouths of Logan and Green Canyons and the lower roll of the Oscar Meyer slide path in Dry Canyon.  Recent local activity has been confined to new or freshly drifted snow, and I suspect that most of the culprit instabilities have healed.

The additional weight from the productive and snowy week might be just enough to put some slopes on the edge.  The good news is that the Deep Slab instability caused by faceted or sugary snow near the ground is now so deeply buried in many places that your weight alone probably won’t be enough to activate it.  The bad news is that you might not get any tell-tail signs of danger until you actually trigger the slab from a shallow or weak spot.  Potential hard slab avalanches could be several feet deep, very broad and deadly. Possible trigger spots include rocky or generally shallow areas, like cliffy lower elevation areas or upper elevation slopes scoured by previous winds.  Overrunning wind slab avalanches or cornice falls might trigger a deeper release, leading to a much larger avalanche.

Increasing west winds and additional snowfall today will cause a rising danger in exposed terrain.  Watch for freshly formed or building wind slabs, and avoid them on steep slopes at all elevations.  Be wary of the dangerous combination of faceted snow near the ground and recent drifting on slopes with shallow overall snowcover at mid and lower elevations.

               Bottom Line:

  There’s a MODERATE danger and you could trigger wind slab avalanches at any elevation on steep slopes exposed to drifting in the backcountry. Although less probable, deadly triggered deep slab avalanches are still possible on slopes with existing weak snow near the ground, mainly in exposed upper elevation terrain.  Increasing west winds and snowfall today could cause the danger in some areas to rise to CONSIDERABLE or become more widespread.  Use good snow assessment and safe travel techniques to minimize your risks.

               Mountain Weather:

  The National Weather Service continued a Snow and Blowing Snow Advisory for the mountains around Logan until 4:00 this afternoon. Expect 4 to 8 additional inches of accumulation in the mountains and west winds with ridgetop gusts in the 40 to 50 mph range.  The snowfall and winds should taper off by evening.  An even weaker storm will move over the region tomorrow afternoon and evening as a high pressure system builds to our west.  We’ll be in a mostly dry and cold northerly flow for the early part of next week.

General Information:

Check out photos of avalanches in the Logan Area on our images page.

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory

 I'm very interested to know what you're seeing out there.  Please e-mail observations to me at [email protected] or leave me a message at 755-3638, especially if you see or trigger an avalanche in the backcountry. We keep all observations confidential.

This advisory will expire in 24 hours from the posting time.

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content.  This advisory describes general avalanche conditions and local variations always occur.